Preparation, properties and metabolism of retro-3-dehydroretinyl acetate.
1. Treatment of 3-dehydroretinyl acetate with aqueous hydrobromic acid resulted in the formation of retro-3-dehydroretinyl acetate, which, on alkaline hydrolysis, gave the corresponding alcohol. 2. retro-3-Dehydroretinyl acetate was isomerized to 3-dehydrovitamin A when fed to vitamin A-deficient rats. 3. When retro-3-dehydroretinyl acetate was administered orally, it was hydrolysed to retro-3-dehydroretinol in the rat intestine, isomerized to 3-dehydroretinol and esterified before being transported to the liver for storage. 4. When administered intraperitoneally, both 3-dehydrovitamin A and retro-3-dehydrovitamin A were accumulated in liver and other tissues, whereas after enterectomy 3-dehydrovitamin A was not detected anywhere in the body. 5. The small intestine was shown to be the major site of conversion of retro-3-dehydrovitamin A into 3-dehydrovitamin A. 6. The extent of conversion of retro-3-dehydroretinyl acetate into 3-dehydrovitamin A was much smaller than that of the conversion of retro-retinyl acetate into vitamin A. 7. The biological potency of retro-3-dehydroretinyl acetate, determined by the rat-growth assay, was 2.6% of that all-trans-retinyl acetate, when given orally.
D000818:Animals; D001835:Body Weight / Q000187:drug effects; D001965:Bromides; D055598:Chemical Phenomena; D002621:Chemistry; D066298:In Vitro Techniques; D007413:Intestinal Mucosa / Q000378:metabolism; D007421:Intestine, Small / Q000378:metabolism; D008099:Liver / Q000032:analysis / Q000378:metabolism; D051381:Rats; D014801:Vitamin A / Q000008:administration & dosage / Q000032:analysis / Q000378:metabolism / Q000494:pharmacology; D014802:Vitamin A Deficiency / Q000378:metabolism
D001965:Bromides; D014801:Vitamin A